It's fine. When the battery is full, it just wont charge, nothing bad will happen to it.
I believe the computer actually runs a little slower when on battery only, I could be wrong about that - edit: scratch that, that was if you run with the battery removed and just off the power cable.

No worries, I keep mine plugged in all the time. It's stops charging on it's own so it won't affect the battery. There are many people that use their notebooks as desktop replacements so they keep them plugged in all the time. The one's the retail stores are plugged in all the time. They wouldn't keep them plugged in if the battery exploded over time.

Although nothing disastrous should happen, it is recommended to allow your battery to cycle from full charge to empty and back in order to maximize battery life. Leaving it plugged in all the time does not allow for that, as it effectively tops off the battery continuously. The ideal situation is to unplug the charger as soon as the light turns green, use the MBP until the battery completely dies, and then allow it to rest for a while (overnight is best) before recharging. You'll get maximum battery life with minimal overheating issues.

Although nothing disastrous should happen, it is recommended to allow your battery to cycle from full charge to empty and back in order to maximize battery life. Leaving it plugged in all the time does not allow for that, as it effectively tops off the battery continuously. The ideal situation is to unplug the charger as soon as the light turns green, use the MBP until the battery completely dies, and then allow it to rest for a while (overnight is best) before recharging. You'll get maximum battery life with minimal overheating issues.

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You're only meant to do that occasionally, like once every month or two.

As others have said, the charge controller should prevent the battery from being overcharged, thus preventing damage. If you're not using it and are still worried, though, you could unplug it. No harm done either way.

I kept my old Macbook Pro plugged in 99% of the time for just over 4 years. And even on the day I sold it my battery still lasted over 3 hours.

These Apple laptops with the magsafe adapters are designed to stop charging the battery once it hits full. I have been, and plan on continuing to, run my laptop plugged in at work 8 hours a day, 5 days a week. And I'm sure my battery will still hold a full charge for years to come.

I have to say its strange seeing so many battery health topics on this forum. For as long as I can remember, I don't get too bothered about this and just use the laptop as I want to use it. When the battery gets low, I plug it in and when its charged again, off I go. This is often at the end of the day, meaning it will be plugged in charging overnight. I've never had any battery life problems with any of the Mac laptops I've owned, so are some people just unlucky or worrying about nothing thanks to the vast amount of info & advice on forums like this?

I have to say its strange seeing so many battery health topics on this forum. For as long as I can remember, I don't get too bothered about this and just use the laptop as I want to use it. When the battery gets low, I plug it in and when its charged again, off I go. This is often at the end of the day, meaning it will be plugged in charging overnight. I've never had any battery lift problems with any of the Mac laptops I've owned, so are some people just unlucky or worrying about nothing thanks to the vast amount of info & advice on forums like this?

Staff Member

I've done this with all of my PowerBooks, ibooks, MacBook Pros and have yet to have any issues with the battery. The circuitry stops charging the battery when its fully charged.

What are your options if you don't do this
1. remove the battery and run on a/c only? You'll cut the GHz in half (apple reduces the speed when there's no batter)
2. Run on battery and continually drain/charge it. This is even worse for the battery because you exhaust the finite charge cycles in the batter.

All in all, the computer is designed to run on a/c where available and have the battery in laptop even if the battery is fully charged.

Personally I never EVER use my MacbookPro on battery - for well over a year it has died when disconnected for a few minutes (although will drain efficiently on sleep for like ... ever, which has always confused me)

I guess those times where i left it on my fluffy bed and it actually cut out (from heat?) - may not of helped ... but im no expert

My solution is ... I am gonna buy an iMac - So used to not having portability now it seems logical.

Don't unplug it the moment it turns green! Someone gave me the false information that the whole cycle is supposed to happen every day and just yesterday my macbook pro died with the battery at 0% health and no charging capabilities, displaying a "replace it now" message. It was only 2 years old but had over 1000 cycles so make sure you only do the unplug cycle once or twice a month.

Don't unplug it the moment it turns green! Someone gave me the false information that the whole cycle is supposed to happen every day and just yesterday my macbook pro died with the battery at 0% health and no charging capabilities, displaying a "replace it now" message. It was only 2 years old but had over 1000 cycles so make sure you only do the unplug cycle once or twice a month.

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I know you're new, and this isn't to be rude, but you might want to check the dates on a thread when you make a post. The last post in this thread before you was 3 years ago...I highly doubt the OP is still looking for help.

Don't unplug it the moment it turns green! Someone gave me the false information that the whole cycle is supposed to happen every day and just yesterday my macbook pro died with the battery at 0% health and no charging capabilities, displaying a "replace it now" message. It was only 2 years old but had over 1000 cycles so make sure you only do the unplug cycle once or twice a month.

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Even though this is a 3 year old thread, that is bad advice. You can plug in or unplug any time you want. You certainly can and should put more than just one or two cycles a month on a battery, to keep it healthy. If you had over 1000 cycles on a battery, it was likely time for a replacement, as they aren't designed to last forever. They are consumable items.

Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug at any time, regardless of the charged percentage. Just make sure you don't run on AC power all the time, as your battery needs to be used regularly to stay healthy. This should answer most, if not all, of your battery/charging questions:

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